:root{
  --brand:#1f3a93; --brand2:#2d7ff9; --ink:#0f1729; --mut:#5b6b86; --line:#e4e9f2;
  --bg:#f5f7fb; --card:#fff; --ok:#16a34a; --err:#dc2626; --code:#0f1729;
  --radius:16px; --shadow:0 10px 30px rgba(17,25,45,.08);
}
*{box-sizing:border-box}
html,body{margin:0}
body{font-family:"Poppins","Cairo",system-ui,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.65}
html[dir="rtl"] body,[dir="rtl"]{font-family:"Cairo","Poppins",system-ui,Arial,sans-serif}
a{color:var(--brand)}
img{max-width:100%}
.wrap{max-width:900px;margin:0 auto;padding:0 18px}

header.top{background:#0f1729;color:#fff;position:sticky;top:0;z-index:20}
.top .wrap{max-width:1080px;display:flex;align-items:center;justify-content:space-between;padding-block:12px;gap:12px}
.brand{display:flex;align-items:center;gap:10px;font-weight:800;font-size:18px;color:#fff;text-decoration:none}
.brand img{width:32px;height:32px;border-radius:8px}
.top-actions{display:flex;align-items:center;gap:10px}
.lang-btn{background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.22);color:#fff;border-radius:999px;padding:7px 15px;font:inherit;font-weight:700;cursor:pointer}
.lang-btn[disabled]{opacity:.6;cursor:default}
.crumb{color:#c7d2e8;text-decoration:none;font-size:14px}

/* ---- lesson ---- */
.lesson-hero{padding:30px 0 6px}
.kicker{display:inline-block;background:#eaf0ff;color:var(--brand);font-weight:800;font-size:12px;letter-spacing:.4px;text-transform:uppercase;padding:6px 12px;border-radius:999px}
.lesson-hero h1{font-size:32px;line-height:1.2;margin:12px 0 4px;font-weight:800}
.lesson-hero .lead{color:var(--mut);font-size:17px;margin:6px 0 0}

.content{padding:8px 0 10px}
.video{position:relative;aspect-ratio:16/9;margin:0 0 22px;border-radius:14px;overflow:hidden;background:#000;box-shadow:var(--shadow)}
.video iframe,.video video{position:absolute;inset:0;width:100%;height:100%;border:0}
.content h2{font-size:23px;margin:30px 0 8px;font-weight:800;color:#132145}
.content h3{font-size:18px;margin:22px 0 6px;font-weight:700;color:#1c2a52}
.content p{margin:10px 0}
.content ul{margin:10px 0;padding-inline-start:22px}
.content li{margin:7px 0}
.content strong,.content b{color:#132145}

/* ---- imported espBlockly lesson content ---- */
.content .header-1{font-size:23px;margin:30px 0 8px;font-weight:800;color:#132145}
.content .header-2{font-size:18px;margin:22px 0 6px;font-weight:700;color:#1c2a52}
.content .list-unordered-1{display:flex;gap:10px;align-items:flex-start;margin:7px 0;list-style:none;padding:0}
.content .list-unordered-1 .bullet.icon{display:block;width:8px;height:8px;border-radius:50%;background:var(--brand2);margin-top:8px;flex:none}
.content .list-unordered-1 .bullet.line{display:none}
.content .list-unordered-1 > div:first-child{flex:none}
.content ul:has(> .list-unordered-1){padding:0;list-style:none}
.content .hardware-table{border-collapse:collapse;margin:12px 0;font-size:15px}
.content .hardware-table td{border:1px solid var(--line);padding:7px 12px}
.content .word-GND{color:#64748b;font-weight:700}
.content .word-VCC{color:#dc2626;font-weight:700}
.content .word-common,.content .pin-name{font-weight:700}
.content .highlight-text-1{background:#fff3cd;padding:1px 6px;border-radius:5px;font-weight:600}
.content .image{margin:14px 0}
.content .image img,.content img{max-width:100%;height:auto;border-radius:10px;border:1px solid var(--line)}
.content .fritzing{font-size:12px;color:var(--mut);margin-top:4px}
.content .code-container{position:relative}
.content .bb-blocks-todo{background:#fff7ed;border:1px dashed #fdba74;color:#9a3412;border-radius:10px;padding:10px 14px;margin:16px 0 6px;font-size:14px;font-weight:500}

/* ---- "Build it with blocks" — block-first teaching (mirrors the BrainBrick IDE) ---- */
.bb-blocks{background:#f7f9fc;border:1px solid var(--line);border-radius:14px;padding:16px 18px;margin:18px 0}
.bb-blocks .bbk-title{font-weight:800;color:#132145;font-size:15px;margin:0 0 12px;display:flex;align-items:center;gap:7px}
.bbk-prog{display:flex;flex-direction:column;gap:4px;max-width:560px}
.bbk{position:relative;color:#fff;font-weight:600;font-size:14px;padding:9px 14px;border-radius:8px;box-shadow:0 1px 2px rgba(0,0,0,.18);line-height:1.45}
.bbk b{font-weight:800;background:rgba(255,255,255,.24);padding:1px 8px;border-radius:5px;margin:0 1px;display:inline-block}
.bbk.out{background:#d34671}    /* Output: LED, relay, buzzer, motor, OLED */
.bbk.in{background:#7cc576}     /* Input: button, sensors, serial-in, touch, BT */
.bbk.time{background:#8d44aa}   /* Time: delay, millis */
.bbk.ctrl{background:#ff9a0e}   /* Control: forever, while, if/else */
.bbk.var{background:#4a8bdf}    /* Variables / math */
.bbk.adv{background:#5b6b86}    /* Advanced / other */
/* wrapper (hat) block — forever / if / do — holds a nested body of chips */
.bbk-wrap{border-radius:10px;padding:8px;margin:0}
.bbk-wrap.ctrl{background:#ff9a0e}
.bbk-wrap.in{background:#7cc576}
.bbk-wrap.time{background:#8d44aa}
.bbk-head{color:#fff;font-weight:800;font-size:14px;padding:3px 6px 8px}
.bbk-head b{font-weight:800;background:rgba(255,255,255,.24);padding:1px 8px;border-radius:5px}
.bbk-body{display:flex;flex-direction:column;gap:4px;background:rgba(255,255,255,.16);border-radius:8px;padding:8px;margin-left:12px}
.bbk-else{color:#fff;font-weight:800;font-size:14px;padding:6px 6px 3px}
.bbk-note{color:var(--mut);font-size:13.5px;margin:12px 0 2px;line-height:1.6}
.bbk-note b{color:#132145}

/* ---- Board Pinout reference (lesson content) ---- */
.content .legend{display:flex;flex-wrap:wrap;gap:8px 14px;margin:14px 0 6px}
.content .legend span{display:inline-flex;align-items:center;gap:7px;font-size:13px;color:var(--mut)}
.content .dot{width:13px;height:13px;border-radius:4px;display:inline-block;flex:none}
.d-out{background:#d34671}.d-in{background:#7cc576}.d-adv{background:#5b6b86}.d-pwr{background:#e0b100}.d-i2c{background:#2d7ff9}
.pintbl{width:100%;border-collapse:collapse;margin:12px 0 6px;font-size:14.5px}
.pintbl th,.pintbl td{border:1px solid var(--line);padding:9px 12px;text-align:left;vertical-align:middle}
.pintbl th{background:#eef2fa;color:#132145;font-weight:800;font-size:13px;text-transform:uppercase;letter-spacing:.3px}
.pintbl tr:nth-child(even) td{background:#fbfcfe}
.gpio{font-family:ui-monospace,Consolas,monospace;font-weight:800;color:#fff;background:#132145;border-radius:6px;padding:2px 9px;display:inline-block;font-size:13.5px}
.cat{width:11px;height:26px;border-radius:4px;display:inline-block}
.c-out{background:#d34671}.c-in{background:#7cc576}.c-adv{background:#5b6b86}.c-pwr{background:#e0b100}.c-i2c{background:#2d7ff9}
.blk{color:#fff;font-weight:700;font-size:12.5px;border-radius:6px;padding:3px 9px;display:inline-block}
.b-out{background:#d34671}.b-in{background:#7cc576}.b-adv{background:#5b6b86}
.free-grid{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:14px 0}
.free-card{border:1px solid var(--line);border-radius:14px;padding:14px 16px;background:var(--card);box-shadow:var(--shadow)}
.free-card h4{margin:0 0 4px;font-size:15px;display:flex;align-items:center;gap:8px}
.free-card p{margin:2px 0 10px;color:var(--mut);font-size:13px}
.chips{display:flex;flex-wrap:wrap;gap:7px}
.chip{font-family:ui-monospace,Consolas,monospace;font-weight:800;color:#fff;border-radius:7px;padding:5px 11px;font-size:14px}
.chip.in{background:#7cc576}.chip.out{background:#d34671}.chip.pwr{background:#e0b100;color:#3a2f00}.chip.i2c{background:#2d7ff9}
@media (max-width:640px){ .free-grid{grid-template-columns:1fr} .pintbl{font-size:13px} .pintbl th,.pintbl td{padding:7px 8px} }
.callout{background:#fff;border:1px solid var(--line);border-inline-start:5px solid var(--brand2);border-radius:12px;padding:14px 18px;margin:16px 0;box-shadow:var(--shadow)}
.callout.def{border-inline-start-color:var(--brand)}
.callout .t{font-weight:800;color:var(--brand);margin:0 0 4px;font-size:14px;text-transform:uppercase;letter-spacing:.4px}

.grid2{display:grid;grid-template-columns:1fr 1fr;gap:14px;margin:14px 0}
.mini{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 16px}
.mini h4{margin:0 0 6px;color:var(--brand);font-size:15px}

pre.code{background:var(--code);color:#e6edf6;border-radius:12px;padding:16px 18px;overflow-x:auto;font:500 14px/1.6 "SFMono-Regular",Consolas,Menlo,monospace;margin:14px 0}
pre.code .cm{color:#8aa0c6}
pre.code .kw{color:#79c0ff}
.pipeline{background:#0f1729;color:#cfe0ff;border-radius:12px;padding:18px;overflow-x:auto;text-align:center;font:600 14px/1.7 "SFMono-Regular",Consolas,Menlo,monospace;margin:16px 0}
.pipeline b{color:#ffd479}

.analogy{background:#f0f6ff;border:1px solid #d7e5ff;border-radius:14px;padding:16px 20px;margin:18px 0}
.analogy .t{font-weight:800;color:var(--brand);margin:0 0 8px}
.analogy ol{margin:0;padding-inline-start:20px}
.analogy li{margin:8px 0}

.cta{margin:26px 0 40px;background:linear-gradient(135deg,#1f3a93,#2d7ff9);border-radius:18px;padding:26px;color:#fff;text-align:center;box-shadow:var(--shadow)}
.cta h3{margin:0 0 6px;font-size:22px}
.cta p{margin:0 0 16px;opacity:.9}
.btn{display:inline-block;background:#fff;color:var(--brand);text-decoration:none;font-weight:800;border:0;border-radius:12px;padding:14px 26px;font:inherit;font-weight:800;cursor:pointer}
.btn.dark{background:var(--brand);color:#fff}

/* ---- portal index ---- */
.lessons{display:grid;gap:14px;margin:22px 0 50px}
.lcard{display:flex;gap:16px;align-items:center;background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px 18px;box-shadow:var(--shadow);text-decoration:none;color:inherit}
.lcard .num{flex:none;width:46px;height:46px;border-radius:12px;background:#eaf0ff;color:var(--brand);display:grid;place-items:center;font-weight:800;font-size:18px}
.lcard h3{margin:0 0 2px;font-size:17px}
.lcard p{margin:0;color:var(--mut);font-size:14px}
.lcard.soon{opacity:.6;pointer-events:none}
.pill{margin-inline-start:auto;font-size:12px;font-weight:700;color:var(--ok);background:#e7f6ee;border-radius:999px;padding:5px 11px}
.pill.soon{color:var(--mut);background:#eef1f6}

/* ---- quiz ---- */
.quiz-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:26px;margin:24px 0 50px}
.quiz-card h2{margin:0 0 6px}
.q-sub{color:var(--mut);margin:0 0 18px}
.q-name{display:block;font-weight:700;margin:0 0 16px}
.q-name input{display:block;width:100%;margin-top:7px;padding:13px;border:1px solid var(--line);border-radius:11px;font:inherit;background:#fbfcfe}
.q-name input:focus{outline:none;border-color:var(--brand2);box-shadow:0 0 0 3px rgba(45,127,249,.15)}
.q-btn{background:var(--brand);color:#fff;border:0;border-radius:12px;padding:14px 22px;font:inherit;font-weight:800;font-size:16px;cursor:pointer}
.q-btn:hover{background:#182e75}
.q-btn.ghost{background:#eef1f6;color:var(--brand)}

.quiz-head{display:flex;justify-content:space-between;align-items:center;gap:10px;margin-bottom:14px}
.quiz-head h2{margin:0}
.q-who{font-weight:700;color:var(--brand);background:#eaf0ff;border-radius:999px;padding:6px 13px;font-size:14px}
.q-block{border:1px solid var(--line);border-radius:14px;padding:16px 18px;margin:14px 0;background:#fff}
.q-text{font-weight:600;margin-bottom:10px}
.q-opt{display:flex;gap:11px;align-items:flex-start;border:1.5px solid var(--line);border-radius:11px;padding:12px 14px;margin:8px 0;cursor:pointer;background:#fbfcfe}
.q-opt:has(input:checked){border-color:var(--brand2);background:#f0f6ff}
.q-opt input{margin-top:3px}

.result .r-badge{width:96px;height:96px;border-radius:50%;display:grid;place-items:center;font-size:30px;font-weight:800;margin:0 auto 12px;color:#fff}
.result .r-badge.ok{background:var(--ok)} .result .r-badge.no{background:var(--err)}
.result h2{text-align:center;margin:0 0 4px}
.r-msg{text-align:center;color:var(--mut);margin:0 0 18px}
.r-review .r-q{border:1px solid var(--line);border-radius:12px;padding:14px 16px;margin:12px 0}
.r-opt{display:flex;gap:9px;align-items:center;padding:9px 12px;border-radius:9px;margin:5px 0;font-size:15px}
.r-opt .r-mark{width:18px;font-weight:800}
.r-opt.right{background:#e7f6ee;color:#0f7a37} .r-opt.right .r-mark{color:var(--ok)}
.r-opt.wrong{background:#fdecec;color:#a11} .r-opt.wrong .r-mark{color:var(--err)}
.r-actions{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:20px}

footer{background:#0f1729;color:#9fb0cf;padding:22px 0;font-size:13px;text-align:center}
[hidden]{display:none!important}
@media (max-width:720px){ .grid2{grid-template-columns:1fr} .lesson-hero h1{font-size:26px} }